In the art of recording conversations between persons, portable audio recorders are well known. With such recorders a portable microphone is associated with the sound recording apparatus, and the audio recorder records the conversation at the same time the participants in the conversation are conversing. The microphone is often integrated into the structure of the recorder. Otherwise, a portable microphone is connected to the sound recording apparatus by a wire conductor. Although such a conventional portable audio recorder is suitable for recording conversations between persons having a face-to-face conversation, such a sound recording system is not suitable for recording telephone conversations as they are being conducted using a handheld held telephone receiver.
Telephone conversations conducted over a telephone equipped with a room speaker, commonly known as a speaker phone, can be recorded by conventional portable audio recording apparatus. However, when the telephone conversation is conducted using a hand-held receiver, conventional portable audio recording apparatus is not suitable.
Special transducers are known for recording telephone conversations conducted with hand-held telephone receivers. Such special transducers are adapted to physically contact a portion of the hand-held receiver at a location somewhere near the portion of the receiver that contacts the pinna portion of the ear of the user. Such known telephone transducers receive sound waves conducted through the body of the telephone receiver by maintaining a close physical contact therewith. They do not pick up sound waves from the air as does a conventional microphone. Such telephone transducers are generally of two types: a transducer having a ring-like adaptor for contacting the transducer with the telephone receiver; and a transducer having a suction cup for securing the telephone transducer onto the telephone receiver.
Both types of known transducers for hand-held telephone receivers have significant problems associated with their use. One problem relates to the conduction of sound through the telephone receiver to the telephone transducer. Not all telephone receivers are fabricated from materials which conduct sound efficiently. When conventional telephone transducers are employed with telephone receivers fabricated from materials which do not conduct sound efficiently, the sound transmitted through the telephone receiver to the telephone transducer ranges from poor to nonexistent. Therefore, it would be desirable to have a telephone sound pick up device whose operation does not depend upon sound transmitted through the body of the telephone receiver to the transducer.
Another problem associated with conventional transducers for recording telephone conversations is the effectiveness of physical contact between the telephone transducer and the telephone receiver. For example, the ring-like adaptor for a conventional telephone transducer may be formed in the shape of a circle and my not be effectively adapted for use on a telephone receiver having a square shaped earpiece. As another example, the suction cup adaptor for a telephone transducer may not readily maintain adequate suction if the suction cup or the telephone earpiece gets dirty. It is most disconcerting to have a suction cup type telephone transducer pop off of the telephone in the middle of an important conversation. Therefore, it would be desirable to have a telephone sound pick up device whose operation does not depend upon physical contact between a transducer adaptor and the body of the telephone receiver.
Another way to record telephone conversations is to have an audio recorder electrically connected to the telephone. With this arrangement, audio information is recorded directly as electrical information without passing through a conversion to sound energy. This method of recording telephone conversations is more expensive and complex than the use of a conventional audio recorder in a proprietary office environment, but this method is impossible to use when the telephone does not belong to the user such as a telephone in a public telephone booth. Therefore, it would be desirable to provide a telephone conversation recording system which does not require electrical connection to the telephone that is used and is capable of recording conversations using non-owned telephones such as in a public telephone booth.
Portable audio tape recorders and playback devices generally include a speaker so that playback of recorded sound is audible to the user. The speaker is generally housed in the general housing for the tape recorder, and the played back sound is audible to anyone who might be present in the general vicinity of the person using the recorder in the playback mode. Some recorders, however, are equipped with add-on ear speakers which bring the recorded sound directly to the ear of the user thereby providing greater privacy and causing less audible disturbance to persons in the general vicinity. Therefore, it would be desirable to provide an audio tape recorder and playback system that provides for recording telephone conversations and also permits playback of the conversations directly to an ear of the user.
A portable audio tape recorder and playback device generally includes a microphone for recording sound and a speaker for playing back recorded sounds. It would be desirable, however, to provide a single microphone/speaker that both records sounds when the tape recorder is in the record mode and that also serves as a speaker to play back recorded sounds when the recorder is used in the play back mode.
Add-on ear speakers for audio playback devices are generally not marketed as microphones and are not suitable for use as a microphone for recording telephone conversations. More specifically, the ear speaker may be an electromagnetic transducer that is housed in a housing that is relatively large; that is too large to fit into the air space present when a telephone ear piece is placed in contact with the ear of the listener. Because add-on ear speakers are relatively inexpensive and are readily available, especially electromagnetic add-on ear speakers, it would be desirable to modify an add-on ear speaker so that it is small enough to fit in the air space between the telephone ear piece and the ear of the listener.
During the course of a telephone conversation, except for a speaker phone, a listener generally has his or her ear in contact with the telephone earpiece. The air space present between the telephone earpiece and the listener's ear serves as an effective sound chamber for conducting both sides of the telephone conversation to the listener's ear. Nevertheless, the prior art methods of recording telephone conversations do not take advantage of the desirable sound characteristics of this sound chamber. More specifically, the suction cup transducer and the ring-like transducer attach to the telephone earpiece outside this sound chamber. Therefore, it would be desirable to provide a transducer for recording telephone conversations that is placed in the sound chamber between a telephone earpiece and the ear of the listener.